
package com.yadong.smarthome2.protocol2;

public class Test {
    public static void main(String[] args) {
        StringBuilder sb = new StringBuilder();
        sb.append("a");
        sb.append("b");
        String s1 = sb.toString();
        sb.append("c");
        sb.append("d");
        String s2 = sb.toString();
        System.out.println(s1 + " " + s2);
    }
}
